Civ IV BTS was a big leap as they incorporated ideas from a mod as you say. It's rare for game companies to do this for some reason. I still get crushed on the higher levels and if they would just give it a graphical face lift I'd still be playing it frequently. I finally got Civ V to work on my Win 10 rig and started a run through with Vox Populi. So far been impressed with it.